2-72182906-C-A

Position:

• chr2-72182906-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_001321729.2(EXOC6B):​c.2310-1G>T variant causes a splice acceptor, intron change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: EXOC6B NM_001321729.2 splice_acceptor, intron
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.37

Genes affected

EXOC6B (HGNC:17085): (exocyst complex component 6B) This gene encodes a protein which is a part of the evolutionarily conserved exocyst, a multimeric protein complex necessary for exocytosis, which in turn, is crucial for cell growth, polarity and migration. Disruption of this gene may be associated with phenotypes exhibiting multiple symptoms including intellectual disability and developmental delay (DD). [provided by RefSeq, Jun 2016]

EXOC6B (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.0044934643 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.3, offset of 9, new splice context is: ttccgccctatgatatctAGaga. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-72182906-C-A is Pathogenic according to our data. Variant chr2-72182906-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2125741.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
EXOC6B	NM_015189.3	c.2309+1169G>T		intron_variant		ENST00000272427.11	NP_056004.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
EXOC6B	ENST00000272427.11	c.2309+1169G>T		intron_variant		1	NM_015189.3	ENSP00000272427.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 21, 2023

This variant has not been reported in the literature in individuals affected with EXOC6B-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change affects an acceptor splice site in intron 21 of the EXOC6B gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in EXOC6B are known to be pathogenic (PMID: 26669664, 36150098). ClinVar contains an entry for this variant (Variation ID: 2125741). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.26
CADD	Benign	19
DANN	Benign	0.76
FATHMM_MKL	Uncertain	0.89	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-72410035;